From: Yu-cheng Yu <yu-cheng.yu@intel.com> To: x86@kernel.org, "H. Peter Anvin" <hpa@zytor.com>, Thomas Gleixner <tglx@linutronix.de>, Ingo Molnar <mingo@redhat.com>, linux-kernel@vger.kernel.org, linux-doc@vger.kernel.org, linux-mm@kvack.org, linux-arch@vger.kernel.org, linux-api@vger.kernel.org, Arnd Bergmann <arnd@arndb.de>, Andy Lutomirski <luto@amacapital.net>, Balbir Singh <bsingharora@gmail.com>, Borislav Petkov <bp@alien8.de>, Cyrill Gorcunov <gorcunov@gmail.com>, Dave Hansen <dave.hansen@linux.intel.com>, Eugene Syromiatnikov <esyr@redhat.com>, Florian Weimer <fweimer@redhat.com>, "H.J. Lu" <hjl.tools@gmail.com>, Jann Horn <jannh@google.com>, Jonathan Corbet <corbet@lwn.net>, Kees Cook <keescook@chromium.org>, Mike Kravetz <mike.kravetz@oracle.com>, Nadav Amit <nadav.amit@gmail.com>, Oleg Nesterov <oleg@redhat.com>, Pavel Machek <pavel@ucw.cz>, Peter Zijlstra <peterz@infradead.org>, Randy Dunlap <rdunlap@infradead.org>, "Ravi V. Shankar" <ravi.v.shankar@intel.com>, Vedvyas Shanbhogue <vedvyas.shanbhogue@intel.com>, Dave Martin <Dave.Martin@arm.com> Cc: Yu-cheng Yu <yu-cheng.yu@intel.com> Subject: [PATCH v7 14/27] x86/mm: Shadow stack page fault error checking Date: Thu, 6 Jun 2019 13:06:33 -0700 [thread overview] Message-ID: <20190606200646.3951-15-yu-cheng.yu@intel.com> (raw) In-Reply-To: <20190606200646.3951-1-yu-cheng.yu@intel.com> If a page fault is triggered by a shadow stack access (e.g. call/ret) or shadow stack management instructions (e.g. wrussq), then bit[6] of the page fault error code is set. In access_error(), verify a shadow stack page fault is within a shadow stack memory area. It is always an error otherwise. For a valid shadow stack access, set FAULT_FLAG_WRITE to effect copy-on-write. Signed-off-by: Yu-cheng Yu <yu-cheng.yu@intel.com> --- arch/x86/include/asm/traps.h | 2 ++ arch/x86/mm/fault.c | 18 ++++++++++++++++++ 2 files changed, 20 insertions(+) diff --git a/arch/x86/include/asm/traps.h b/arch/x86/include/asm/traps.h index 5906a22796b6..292fb3a1b340 100644 --- a/arch/x86/include/asm/traps.h +++ b/arch/x86/include/asm/traps.h @@ -166,6 +166,7 @@ enum { * bit 3 == 1: use of reserved bit detected * bit 4 == 1: fault was an instruction fetch * bit 5 == 1: protection keys block access + * bit 6 == 1: shadow stack access fault */ enum x86_pf_error_code { X86_PF_PROT = 1 << 0, @@ -174,5 +175,6 @@ enum x86_pf_error_code { X86_PF_RSVD = 1 << 3, X86_PF_INSTR = 1 << 4, X86_PF_PK = 1 << 5, + X86_PF_SHSTK = 1 << 6, }; #endif /* _ASM_X86_TRAPS_H */ diff --git a/arch/x86/mm/fault.c b/arch/x86/mm/fault.c index 46df4c6aae46..59f4f66e4f2e 100644 --- a/arch/x86/mm/fault.c +++ b/arch/x86/mm/fault.c @@ -1205,6 +1205,17 @@ access_error(unsigned long error_code, struct vm_area_struct *vma) (error_code & X86_PF_INSTR), foreign)) return 1; + /* + * Verify X86_PF_SHSTK is within a shadow stack VMA. + * It is always an error if there is a shadow stack + * fault outside a shadow stack VMA. + */ + if (error_code & X86_PF_SHSTK) { + if (!(vma->vm_flags & VM_SHSTK)) + return 1; + return 0; + } + if (error_code & X86_PF_WRITE) { /* write, present and write, not present: */ if (unlikely(!(vma->vm_flags & VM_WRITE))) @@ -1362,6 +1373,13 @@ void do_user_addr_fault(struct pt_regs *regs, perf_sw_event(PERF_COUNT_SW_PAGE_FAULTS, 1, regs, address); + /* + * If the fault is caused by a shadow stack access, + * i.e. CALL/RET/SAVEPREVSSP/RSTORSSP, then set + * FAULT_FLAG_WRITE to effect copy-on-write. + */ + if (hw_error_code & X86_PF_SHSTK) + flags |= FAULT_FLAG_WRITE; if (hw_error_code & X86_PF_WRITE) flags |= FAULT_FLAG_WRITE; if (hw_error_code & X86_PF_INSTR) -- 2.17.1
WARNING: multiple messages have this Message-ID (diff)
From: Yu-cheng Yu <yu-cheng.yu@intel.com> To: x86@kernel.org, "H. Peter Anvin" <hpa@zytor.com>, Thomas Gleixner <tglx@linutronix.de>, Ingo Molnar <mingo@redhat.com>, linux-kernel@vger.kernel.org, linux-doc@vger.kernel.org, linux-mm@kvack.org, linux-arch@vger.kernel.org, linux-api@vger.kernel.org, Arnd Bergmann <arnd@arndb.de>, Andy Lutomirski <luto@amacapital.net>, Balbir Singh <bsingharora@gmail.com>, Borislav Petkov <bp@alien8.de>, Cyrill Gorcunov <gorcunov@gmail.com>, Dave Hansen <dave.hansen@linux.intel.com>, Eugene Syromiatnikov <esyr@redhat.com>, Florian Weimer <fweimer@redhat.com>, "H.J. Lu" <hjl.tools@gmail.com>, Jann Horn <jannh@google.com>, Jonathan Corbet <corbet@lwn.net>, Kees Cook <keescook@chromium.org>, Mike Kravetz <mike.kravetz@oracle.com>, Nadav Amit <nadav.amit@gmail.com> Cc: Yu-cheng Yu <yu-cheng.yu@intel.com> Subject: [PATCH v7 14/27] x86/mm: Shadow stack page fault error checking Date: Thu, 6 Jun 2019 13:06:33 -0700 [thread overview] Message-ID: <20190606200646.3951-15-yu-cheng.yu@intel.com> (raw) In-Reply-To: <20190606200646.3951-1-yu-cheng.yu@intel.com> If a page fault is triggered by a shadow stack access (e.g. call/ret) or shadow stack management instructions (e.g. wrussq), then bit[6] of the page fault error code is set. In access_error(), verify a shadow stack page fault is within a shadow stack memory area. It is always an error otherwise. For a valid shadow stack access, set FAULT_FLAG_WRITE to effect copy-on-write. Signed-off-by: Yu-cheng Yu <yu-cheng.yu@intel.com> --- arch/x86/include/asm/traps.h | 2 ++ arch/x86/mm/fault.c | 18 ++++++++++++++++++ 2 files changed, 20 insertions(+) diff --git a/arch/x86/include/asm/traps.h b/arch/x86/include/asm/traps.h index 5906a22796b6..292fb3a1b340 100644 --- a/arch/x86/include/asm/traps.h +++ b/arch/x86/include/asm/traps.h @@ -166,6 +166,7 @@ enum { * bit 3 == 1: use of reserved bit detected * bit 4 == 1: fault was an instruction fetch * bit 5 == 1: protection keys block access + * bit 6 == 1: shadow stack access fault */ enum x86_pf_error_code { X86_PF_PROT = 1 << 0, @@ -174,5 +175,6 @@ enum x86_pf_error_code { X86_PF_RSVD = 1 << 3, X86_PF_INSTR = 1 << 4, X86_PF_PK = 1 << 5, + X86_PF_SHSTK = 1 << 6, }; #endif /* _ASM_X86_TRAPS_H */ diff --git a/arch/x86/mm/fault.c b/arch/x86/mm/fault.c index 46df4c6aae46..59f4f66e4f2e 100644 --- a/arch/x86/mm/fault.c +++ b/arch/x86/mm/fault.c @@ -1205,6 +1205,17 @@ access_error(unsigned long error_code, struct vm_area_struct *vma) (error_code & X86_PF_INSTR), foreign)) return 1; + /* + * Verify X86_PF_SHSTK is within a shadow stack VMA. + * It is always an error if there is a shadow stack + * fault outside a shadow stack VMA. + */ + if (error_code & X86_PF_SHSTK) { + if (!(vma->vm_flags & VM_SHSTK)) + return 1; + return 0; + } + if (error_code & X86_PF_WRITE) { /* write, present and write, not present: */ if (unlikely(!(vma->vm_flags & VM_WRITE))) @@ -1362,6 +1373,13 @@ void do_user_addr_fault(struct pt_regs *regs, perf_sw_event(PERF_COUNT_SW_PAGE_FAULTS, 1, regs, address); + /* + * If the fault is caused by a shadow stack access, + * i.e. CALL/RET/SAVEPREVSSP/RSTORSSP, then set + * FAULT_FLAG_WRITE to effect copy-on-write. + */ + if (hw_error_code & X86_PF_SHSTK) + flags |= FAULT_FLAG_WRITE; if (hw_error_code & X86_PF_WRITE) flags |= FAULT_FLAG_WRITE; if (hw_error_code & X86_PF_INSTR) -- 2.17.1
next prev parent reply other threads:[~2019-06-06 20:15 UTC|newest] Thread overview: 161+ messages / expand[flat|nested] mbox.gz Atom feed top 2019-06-06 20:06 [PATCH v7 00/27] Control-flow Enforcement: Shadow Stack Yu-cheng Yu 2019-06-06 20:06 ` Yu-cheng Yu 2019-06-06 20:06 ` [PATCH v7 01/27] Documentation/x86: Add CET description Yu-cheng Yu 2019-06-06 20:06 ` Yu-cheng Yu 2019-06-06 20:06 ` [PATCH v7 02/27] x86/cpufeatures: Add CET CPU feature flags for Control-flow Enforcement Technology (CET) Yu-cheng Yu 2019-06-06 20:06 ` Yu-cheng Yu 2019-06-06 20:06 ` [PATCH v7 03/27] x86/fpu/xstate: Change names to separate XSAVES system and user states Yu-cheng Yu 2019-06-06 20:06 ` Yu-cheng Yu 2019-06-06 20:06 ` [PATCH v7 04/27] x86/fpu/xstate: Introduce XSAVES system states Yu-cheng Yu 2019-06-06 20:06 ` Yu-cheng Yu 2019-06-06 21:18 ` Dave Hansen 2019-06-06 21:18 ` Dave Hansen 2019-06-06 22:04 ` Andy Lutomirski 2019-06-06 22:04 ` Andy Lutomirski 2019-06-06 22:08 ` Dave Hansen 2019-06-06 22:08 ` Dave Hansen 2019-06-06 22:10 ` Yu-cheng Yu 2019-06-06 22:10 ` Yu-cheng Yu 2019-06-06 22:10 ` Yu-cheng Yu 2019-06-07 1:54 ` Andy Lutomirski 2019-06-07 1:54 ` Andy Lutomirski 2019-06-06 20:06 ` [PATCH v7 05/27] x86/fpu/xstate: Add XSAVES system states for shadow stack Yu-cheng Yu 2019-06-06 20:06 ` Yu-cheng Yu 2019-06-07 7:07 ` Peter Zijlstra 2019-06-07 7:07 ` Peter Zijlstra 2019-06-07 16:14 ` Yu-cheng Yu 2019-06-07 16:14 ` Yu-cheng Yu 2019-06-07 16:14 ` Yu-cheng Yu 2019-06-06 20:06 ` [PATCH v7 06/27] x86/cet: Add control protection exception handler Yu-cheng Yu 2019-06-06 20:06 ` Yu-cheng Yu 2019-06-06 20:06 ` [PATCH v7 07/27] x86/cet/shstk: Add Kconfig option for user-mode shadow stack Yu-cheng Yu 2019-06-06 20:06 ` Yu-cheng Yu 2019-06-06 20:06 ` [PATCH v7 08/27] mm: Introduce VM_SHSTK for shadow stack memory Yu-cheng Yu 2019-06-06 20:06 ` Yu-cheng Yu 2019-06-06 20:06 ` [PATCH v7 09/27] mm/mmap: Prevent Shadow Stack VMA merges Yu-cheng Yu 2019-06-06 20:06 ` Yu-cheng Yu 2019-06-06 20:06 ` [PATCH v7 10/27] x86/mm: Change _PAGE_DIRTY to _PAGE_DIRTY_HW Yu-cheng Yu 2019-06-06 20:06 ` Yu-cheng Yu 2019-06-06 20:06 ` [PATCH v7 11/27] x86/mm: Introduce _PAGE_DIRTY_SW Yu-cheng Yu 2019-06-06 20:06 ` Yu-cheng Yu 2019-06-06 20:06 ` [PATCH v7 12/27] drm/i915/gvt: Update _PAGE_DIRTY to _PAGE_DIRTY_BITS Yu-cheng Yu 2019-06-06 20:06 ` Yu-cheng Yu 2019-06-06 20:06 ` [PATCH v7 13/27] x86/mm: Modify ptep_set_wrprotect and pmdp_set_wrprotect for _PAGE_DIRTY_SW Yu-cheng Yu 2019-06-06 20:06 ` Yu-cheng Yu 2019-06-06 20:06 ` Yu-cheng Yu [this message] 2019-06-06 20:06 ` [PATCH v7 14/27] x86/mm: Shadow stack page fault error checking Yu-cheng Yu 2019-06-06 20:06 ` [PATCH v7 15/27] mm: Handle shadow stack page fault Yu-cheng Yu 2019-06-06 20:06 ` Yu-cheng Yu 2019-06-07 7:30 ` Peter Zijlstra 2019-06-07 7:30 ` Peter Zijlstra 2019-06-06 20:06 ` [PATCH v7 16/27] mm: Handle THP/HugeTLB " Yu-cheng Yu 2019-06-06 20:06 ` Yu-cheng Yu 2019-06-06 20:06 ` [PATCH v7 17/27] mm: Update can_follow_write_pte/pmd for shadow stack Yu-cheng Yu 2019-06-06 20:06 ` Yu-cheng Yu 2019-06-06 20:06 ` [PATCH v7 18/27] mm: Introduce do_mmap_locked() Yu-cheng Yu 2019-06-06 20:06 ` Yu-cheng Yu 2019-06-07 7:43 ` Peter Zijlstra 2019-06-07 7:43 ` Peter Zijlstra 2019-06-07 7:47 ` Peter Zijlstra 2019-06-07 7:47 ` Peter Zijlstra 2019-06-07 16:16 ` Yu-cheng Yu 2019-06-07 16:16 ` Yu-cheng Yu 2019-06-07 16:16 ` Yu-cheng Yu 2019-06-06 20:06 ` [PATCH v7 19/27] x86/cet/shstk: User-mode shadow stack support Yu-cheng Yu 2019-06-06 20:06 ` Yu-cheng Yu 2019-06-06 20:06 ` [PATCH v7 20/27] x86/cet/shstk: Introduce WRUSS instruction Yu-cheng Yu 2019-06-06 20:06 ` Yu-cheng Yu 2019-06-06 20:06 ` [PATCH v7 21/27] x86/cet/shstk: Handle signals for shadow stack Yu-cheng Yu 2019-06-06 20:06 ` Yu-cheng Yu 2019-06-06 20:06 ` [PATCH v7 22/27] binfmt_elf: Extract .note.gnu.property from an ELF file Yu-cheng Yu 2019-06-06 20:06 ` Yu-cheng Yu 2019-06-07 7:58 ` Peter Zijlstra 2019-06-07 7:58 ` Peter Zijlstra 2019-06-07 16:17 ` Yu-cheng Yu 2019-06-07 16:17 ` Yu-cheng Yu 2019-06-07 16:17 ` Yu-cheng Yu 2019-06-07 18:01 ` Dave Martin 2019-06-07 18:01 ` Dave Martin 2019-06-10 16:29 ` Yu-cheng Yu 2019-06-10 16:29 ` Yu-cheng Yu 2019-06-10 16:29 ` Yu-cheng Yu 2019-06-10 16:57 ` Dave Martin 2019-06-10 16:57 ` Dave Martin 2019-06-10 17:24 ` Florian Weimer 2019-06-10 17:24 ` Florian Weimer 2019-06-10 17:24 ` Florian Weimer 2019-06-11 11:41 ` Dave Martin 2019-06-11 11:41 ` Dave Martin 2019-06-11 19:31 ` Yu-cheng Yu 2019-06-11 19:31 ` Yu-cheng Yu 2019-06-11 19:31 ` Yu-cheng Yu 2019-06-12 9:32 ` Dave Martin 2019-06-12 9:32 ` Dave Martin 2019-06-12 19:04 ` Yu-cheng Yu 2019-06-12 19:04 ` Yu-cheng Yu 2019-06-12 19:04 ` Yu-cheng Yu 2019-06-13 13:26 ` Dave Martin 2019-06-13 13:26 ` Dave Martin 2019-06-17 11:08 ` Florian Weimer 2019-06-17 11:08 ` Florian Weimer 2019-06-17 11:08 ` Florian Weimer 2019-06-17 12:20 ` Thomas Gleixner 2019-06-17 12:20 ` Thomas Gleixner 2019-06-17 12:20 ` Thomas Gleixner 2019-06-18 9:12 ` Dave Martin 2019-06-18 9:12 ` Dave Martin 2019-06-18 12:41 ` Peter Zijlstra 2019-06-18 12:41 ` Peter Zijlstra 2019-06-18 12:47 ` Florian Weimer 2019-06-18 12:47 ` Florian Weimer 2019-06-18 12:47 ` Florian Weimer 2019-06-18 12:55 ` Peter Zijlstra 2019-06-18 12:55 ` Peter Zijlstra 2019-06-18 13:32 ` Dave Martin 2019-06-18 13:32 ` Dave Martin 2019-06-18 13:32 ` Dave Martin 2019-06-18 13:32 ` Dave Martin 2019-06-18 14:58 ` Yu-cheng Yu 2019-06-18 14:58 ` Yu-cheng Yu 2019-06-18 14:58 ` Yu-cheng Yu 2019-06-18 15:49 ` Florian Weimer 2019-06-18 15:49 ` Florian Weimer 2019-06-18 15:49 ` Florian Weimer 2019-06-18 15:53 ` Yu-cheng Yu 2019-06-18 15:53 ` Yu-cheng Yu 2019-06-18 15:53 ` Yu-cheng Yu 2019-06-18 16:05 ` Florian Weimer 2019-06-18 16:05 ` Florian Weimer 2019-06-18 16:05 ` Florian Weimer 2019-06-18 16:00 ` Yu-cheng Yu 2019-06-18 16:00 ` Yu-cheng Yu 2019-06-18 16:00 ` Yu-cheng Yu 2019-06-18 16:20 ` Dave Martin 2019-06-18 16:20 ` Dave Martin 2019-06-18 16:25 ` Florian Weimer 2019-06-18 16:25 ` Florian Weimer 2019-06-18 16:25 ` Florian Weimer 2019-06-18 16:50 ` Dave Martin 2019-06-18 16:50 ` Dave Martin 2019-06-06 20:06 ` [PATCH v7 23/27] x86/cet/shstk: ELF header parsing of Shadow Stack Yu-cheng Yu 2019-06-06 20:06 ` Yu-cheng Yu 2019-06-07 7:54 ` Peter Zijlstra 2019-06-07 7:54 ` Peter Zijlstra 2019-06-06 20:06 ` [PATCH v7 24/27] x86/cet/shstk: Handle thread shadow stack Yu-cheng Yu 2019-06-06 20:06 ` Yu-cheng Yu 2019-06-06 20:06 ` [PATCH v7 25/27] mm/mmap: Add Shadow stack pages to memory accounting Yu-cheng Yu 2019-06-06 20:06 ` Yu-cheng Yu 2019-06-11 17:55 ` Dave Hansen 2019-06-11 17:55 ` Dave Hansen 2019-06-11 19:22 ` Yu-cheng Yu 2019-06-11 19:22 ` Yu-cheng Yu 2019-06-11 19:22 ` Yu-cheng Yu 2019-06-06 20:06 ` [PATCH v7 26/27] x86/cet/shstk: Add arch_prctl functions for Shadow Stack Yu-cheng Yu 2019-06-06 20:06 ` Yu-cheng Yu 2019-06-06 20:06 ` [PATCH v7 27/27] x86/cet/shstk: Add Shadow Stack instructions to opcode map Yu-cheng Yu 2019-06-06 20:06 ` Yu-cheng Yu 2019-11-01 14:03 ` Adrian Hunter 2019-11-01 14:03 ` Adrian Hunter 2019-11-01 14:17 ` Yu-cheng Yu 2019-11-01 14:17 ` Yu-cheng Yu 2019-11-01 14:17 ` Yu-cheng Yu
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